1. Field of the Invention
This invention is directed to obtaining higher accuracy measurements of the rolling stock of a railroad.
2. Related Art
The rolling stock of a railroad, such as box cars, flat cars, tanker cars, hopper cars, gondolas, piggy back carriers for semi-tractor trailers and/or containers, passenger cars, and the like, are subject to wear, fatigue and the like. This is especially true of the wheels and trucks of such rolling stock. Accordingly, it is typically necessary or desirable to inspect such rolling stock, and especially the trucks and wheels of such rolling stock, on occasion to insure that the rolling stock remains safe to use and is not likely to experience a breakdown in the interval between the current inspection and the next inspection of that piece of rolling stock.
Traditionally, such inspections were performed manually. Not only was such manual inspection time consuming and expensive, it was difficult to insure that a given piece of rolling stock was inspected on any reasonable schedule.
Accordingly, as set forth in U.S. Pat. Nos. 6,911,914; 6,909,514; 6,872,945; 6,823,242; 6,768,551; 5,793,492; 5,677,533; 5,596,203; 5,448,072; 5,247,338; 3,253,140; and 3,206,596, each of which is incorporated herein by reference for its teachings, over the last thirty years, various systems and methods have been developed for automatically inspecting various aspects and parameters of railway rolling stock, such as railroad wheel and bearing temperatures, hot rail car surfaces, wheel profiles, and the like. Conventionally, such systems and methods have used passive sensors that generate a 1-dimensional, time-varying signal as the piece of rolling stock passes by the sensor. To provide additional dimensional information, multiple sensors can be arranged either along or perpendicular to the railway rail. More recently, optical-based systems that generate 2-dimensional images of various components of railway rolling stock, such as wheels, truck assemblies, car bodies of the rolling stock and the like, have been used to inspect such rolling stock.